A constantly increasing cooling requirement can be observed in modern motor vehicles, for example in the area of the charge-air cooling, as a result of which the demands on the cooling and air-conditioning systems are constantly increasing. An improved use of heat sources and heat sinks can lead to a greater degree of utilisation and moreover to a reduction in fuel consumption. Cooling systems available on the market at present for charge-air cooling often comprise a stacked-plate heat exchanger which is constituted in one stage. The efficiency that can be achieved with the one-stage temperature regulation is however limited. In order to improve the efficiency of cooling circuits, in particular for the cooling of fluids, such as for example coolants, refrigerants, oil, exhaust air or charge air, it is therefore advisable in some cases to cool and heat a fluid over two stages. The drawback with the two-stage temperature regulation of fluids, however, is that the use of two heat exchangers conventionally connected one after the other is associated with much higher costs and an increase space requirement.
For this reason, a so-called stacked-plate heat exchanger is often used, which comprises both a high-temperature coolant circuit HT as well as a low-temperature coolant circuit NT. The space requirement can be reduced considerably with such a combined stacked-plate heat exchanger. A drawback with such combined stacked-plate heat exchangers, however, is their comparatively complex production.
There is known from DE 10 2005 044 291 A1 a stacked-plate heat exchanger, in particular a charge-air cooler, with a plurality of elongate plates which are stacked upon one another and connected, for example soldered, to one another, which plates delimit a cavity for conducting a medium to be cooled, such as for example charge air, in the longitudinal direction of the plates, and a further cavity for conducting a coolant, wherein the plates comprise in each case an inlet connection and an outlet connection for the medium to be cooled. In order to be able to create a stacked-plate heat exchanger which on the one hand can be produced cost-effectively and on the other hand has a long service life even at high temperatures, at least one coolant connection extends partially around a connection for the medium to be cooled.
A further stacked-plate heat exchanger is known from EP 1 700 079 B1, which is designed to exchange heat between at least one high-temperature fluid and at least one cooling fluid and comprises a plurality of stacked heat exchanger plates soldered to one another, each one of which comprises: an inlet opening for the high-temperature fluid, an outlet opening for the oil fluid, an outlet opening for the high-temperature fluid as well as an inlet opening for the cooling fluid.
A drawback with the stacked-plate heat exchangers known from the prior art, however, is that they too, even in mass production, can only be produced in a comparatively complex way and are therefore expensive.
The present invention is therefore concerned with the problem of providing an improved or at least an alternative embodiment for a stacked-plate heat exchanger of the generic type, said embodiment enabling a two-stage temperature regulation of a medium to be cooled with an increased heat transfer and also being able to be produced at a favourable cost.
According to the invention, this problem is solved by the subject-matter of the independent claims. Advantageous embodiments are the subject-matter of the dependent claims.